1. Field of the Invention
The present invention relates to a machine learning apparatus, a motor control apparatus, a motor control system, and a machine learning method, and specifically relates to a machine learning apparatus for learning operation conditions of a cooling device, a motor control apparatus and a motor control system having the machine learning apparatus, and a machine learning method.
2. Description of Related Art
The temperature of motors increases with their drives due to heat generation caused by an iron loss of a stator core and a copper loss of windings. The increase in temperature may result in a loss of the motor or damage the motor. Thus, in order to provide absorption cooling for the generated heat, a method for cooling the motor is proposed (for example, Japanese Unexamined Patent Publication (Kokai) No. 5-236704, hereinafter referred to as “patent document 1”).
Also, in control apparatuses for driving the motor, a power device generates heat inside the control apparatus with a drive of the motor and an increase in temperature causes damage to the power device. Thus, in order to maintain the life of the control apparatus, a method for cooling the control apparatus is proposed.
A motor cooling device described in the patent document 1 includes a coolant supply pipe disposed inside a rotation shaft of the motor along an axial direction, coolant ejection ports that are provided opposite winding edges formed by windings wound around a stator core to eject a coolant from the coolant supply pipe to the winding edges, a pump for supplying the coolant to the coolant supply pipe, and a pump control means for varying the amount of the coolant discharged from the pump in accordance with a drive state of the motor. The motor cooling device described in the patent document 1 can efficiently cool the stator core, and therefore efficiently cool the entire motor.
However, in the conventional motor control apparatus, only the rate of operation of the cooling device is varied in accordance with the temperature of the motor. Therefore, it is difficult to reduce losses in the motor, the motor control apparatus, and the cooling device, while controlling the motor and the motor control apparatus at a regulated temperature or lower.